Just buy them at Costco. Johnson Controls makes nearly all of Costco's Batteries. And if they fail it's no hassle at all to get them replaced. There are only a handful of battery manufacturers rebranding to all the retail outlets. There is no way for you to really know with some brands if they are coming out of USA, Mexico, or China. So warranty matters. You could always ask this question in Golf Forums and see what kind of batteries are preferred.